flat feet

AUTHOR: Marc Mitnick DPM

Podiatric Medical Review Board

--> flat feet

pes plano valgus, adult acquired flat foot

Flat feet more commonly known as fallen arches is a condition found in both children and adults. In most situations, when the patient is non-weight bearing, there will be some sort of discernible arch, however, that arch quickly disappears when the patients stands up. This distinction needs to be made because there are individuals who exhibit a more rigid flat foot both standing and sitting. These individuals generally have more symptomatic problems and this discussion will briefly look into that condition at the end.

The ‘flexible flat foot’ that we are going to discuss here may occur in one or both feet, and the degree of flattening can vary between the two feet. In many people flat feet are not an issue at all and these people go through life without any foot problems. In others, the long term effects of flat feet can not only lead to foot and ankle pain, but many people will also experience knee, hip and lower back pain as a result of their feet being flat.

Flat feet are common if not almost normal in infants and toddlers simply due to the fact that the arch of the foot has not yet developed. The arch generally will develop during childhood as part of a normal relationship between the foot’s muscles, tendons, ligaments and bone. It is advocated by many that young children should be given the opportunity to walk barefoot particularly over uneven terrain (eg: the beach) in an effort to help strengthen the muscles that originate in the foot.

Theoretically, wearing orthotics at a young age would help develop an arch, but it is generally not a practical maneuver in that the child would have to be wearing his orthotics ALL the time. The reality is that never happens if you stop and think about how often a child is barefoot, at times such as in the morning and evening hours at home, or while at the beach, etc.


What Should You Look for

YOUNG CHILDREN Even though young children will tend to walk flat footed their gait should be observed for any abnormal signs such as limping, clumsiness in gait, or an excessive ‘knock-kneed’ gait. The parent should also observe whether or not the child tends to tire easily during walks or complains of foot or leg pain during extended walks. Parents should also observe their children's shoes for abnormal wear patterns. Additionally, many children who are excessively pronated will experience night cramps. In my practice, this is usually the complaint that makes parents first aware of their child's excessive pronation and brings them into the office.

PRE-TEENS AND TEENAGERS Usually in this age range, parents bring the children in for treatment of their flat feet because the kids have started playing sports and the demands of a lot of running are now beginning to manifest themselves with foot and leg pain as a result of flat feet. The main complaint is that when it comes to running, they cannot seem to keep up and they have pain in their feet and legs that lasts long after the game. Shin splints and heel pain are two common symptoms that are result of flat feet in the young athlete.

ADULTS Flat feet in the adult may either be a direct extension of the condition from youth or can be caused by other factors. These factors include injury, disease such as arthritis or neurological disease, poor biomechanics (a fault in the way the foot functions during gait), excessive weight gain, occupational demands placed on the feet, and hormonal changes seen during pregnancy along with the associated weight gain.

As previously stated a distinction is made in the type of flat foot that a person may exhibit. A rigid flatfoot is one where the foot is flat both on and off weight-bearing as opposed to a flexible flatfoot where off weight-bearing there is some sort of arch but upon standing the arch flattens out.

Note the following diagram of a foot that has flattened out. Because of the excessive movement of the foot and lower leg in the direction of the three arrows this throws off the way the foot will function in the gait cycle.

acquired flatfoot

Because the foot is over stretching or flattening out it is putting excessive strain on the muscles and ligaments that “hold" the foot together. In doing so it forces the muscles in the foot and lower leg to work in an abnormal fashion causing a variety of problems. In addition to the problems already mentioned in children and teens, conditions such as bunions , hammertoes , midtarsal fault, calluses on the ball of the foot can have a flat foot component to their formation. Additionally, runners knee is knee pain seen in flat feet and occurs in both children and adults.


A worsening state of flat feet in the adult is known as adult acquired flat foot, medically known as posterior tibial dysfunction. The etiology, or cause behind its formation, is not completely understood. It can end up being a very difficult condition to treat. In addition the condition seems to have become more prevalent over the last 20 years. The foot is completely flat weight bearing or non-weight bearing.

For years the consensus was that this condition was caused by a loss of function of the posterior tibial muscle, also known as the long flexor tendon, see anatomy diagrams.

In more recent years the general thinking has moved more to a combination of non-function of various parts of the foot primarily the ligament attachments in the rear portion of the foot. This line of thinking would make sense since surgically repairing the tibialis posterior muscle alone rarely solves the problem.

The picture below demonstrates a typical adult-acquired flatfoot.

anatomical flatfoot

Since the foot does not flatten out and collapse like a pancake overnight, it is a progressive deformity and treatment should be instituted according to the degree of deformity that is presented to the doctor. In other words, a patient with a mild case should not look at surgery as a first option, whereby a person with an advanced case may have no other choice other than surgery because anything less will just not work.

consequences in gait from tibialis posterior dysfunction

  • Contact Phase-loss of shock absorption as the heel hits the ground and premature loading of midtarsal joint or middle portion of foot.
  • Midstance Phase-increased collapse of middle portion of foot resulting in breakdown of joints and ligaments and shearing of soft tissue all resulting in pain.
  • Propulsive Phase-as the foot "pushes off" it does so off the inside of the foot which results in loss of propulsive power.
  • Swing Phase-as the affected foot swings forward it results in decreased acceleration of the limb and increased stress on the weightbearing limb.

see gait cycle

INITIAL TREATMENT In the early stages of deformity when you first experience tendonitis, swelling and pain, simple techniques like ice, immobilization and anti-inflammatory medication is probably all that is needed. X-rays may be very helpful in determining the degree of deformity, as well as muscle testing in predicting the possibility of worsening. At this point a simple orthotic may be all that is necessary in stabilizing the foot.

ADVANCED TREATMENT In more advanced stages once the inflammation is reduced thru ice and medication an ankle foot orthosis may be needed to give better support to the mid part of the foot, the rear portion of the foot and the ankle.

Once a patient presents with a completely “broken down" foot conservative therapy will not help. It may offer short term relief but ultimately the patient will have to consider surgical intervention ranging from repair of the tibialis posterior tendon, to associated ligament repair, to bone fusions, where certain bones in the mid and rear portion of the foot are fused to “hold" the foot in an upright position.

There is a procedure which is gaining popularity, known as a subtalar arthroresis. In this procedure a titanium device is placed in the subtalar joint which is the joint that controls pronation or the excessive flattening out of the foot. This device acts as a wedge which then limits the motion of the subtalar joint and thus reduces excessive pronation.

The indications for this procedure are pediatric flexible flat foot, adult flexible flat foot and tibialis posterior dysfunction. The key criteria here is that the foot must be a flexible flat foot (vs. a rigid flatfoot). A flexible flat foot is a foot that is flat during weight bearing but will have some degree of arch when non-weight bearing. A rigid flatfoot is always flat whether weight bearing or non-weight bearing and thus is not a candidate for this procedure.

The procedure itself is a relatively simple procedure but does require the patient to be non-weight bearing for one week post-op and then in a cam walker for three weeks. There may be some residual tenderness in the area as the foot learns to "adjust" to the implant, but in most cases it will subside over time.

If your doctor has recommended this procedure to you, it would be worth your while to consider as it is not difficult to perform and could have lasting improvement in your ability to walk.

orthotics for flat feet

Generally speaking, orthotics are the most common treatment for flat feet. Having said that, because of the differences in the types and degree of flat feet, there is not one simple solution or recommendation. If you feel that you have flat feet and they are the cause of your pain anywhere from your feet to your lower back, going out and trying an inexpensive pair of "arch supports" from a drugstore of supermarket is certainly not a bad idea.

If that solves your problem, fine. If it does not but you do notice some degree of improvement, that should tell you that a custom or prescription orthotic might give you better relief. At that point, a consultation with a podiatrist might not be a bad idea.


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